Improvement in machinery for forging screws



. UNITED STATES PATENi` ENIGE@ IMPROVEMENT IN MACHINERY FOE FORGINGSCREWS.

Specification forming part of Letters Patent No. 54,687, dated May 15,1866.

4To all whom it may concern:

Be it known that I, JOHN CooHRANE, of the township of Wall, county ofMonmouth, and State of New Jersey, have invented a new and usefulMachine for Forging Screw-Threads upon Metal Bolts; and Ido herebydeclare that the following is a full and exact descrip tion thereof,reference being had to the fan- -neXed drawings, and to the figures andletters marked thereon, and in which- Figure l is a side elevation ofthe machine; Fig. 2, afront elevation, andFigs. 3, LI, 5, &c., detailsthereof; and the sameparts are indi- -cated in all the iigures by thesame letters.

^ block-that has an automatic movement to or from the top` die, asrequired in the process. The blank or bolt to be operated upon has aguide-screw ot' the required pitch attached to it or to the tongs bywhich it is held, which guide-screw works in a screwed bearingin thesame axis with the bolt, which stationary bearing of the guide-screwisplaced at a convenient distance from the forging-dies to give propersupport to the bolt or tongs.

The anvil-block is made-to rise and fall as required by means 4ofsliding templets, that are shaped to suit the operation, and when inthedepressed position the heated bolt or blank is passed through betweenthe dies to the full Y extent to which the screw is to be formed on it.The blank-bolt and guide-screw are then gradually rotated with adirection of motion that will cause the guide-screw to draw the `boltoutward through the dies, and thereby cause the forging operation toprogress from Y the neck toward the point ofthe bolt, so that bythe timethe screw is completed it will be entirely withdrawn from the dies. Inthis ina-nner screws may be produced or madeof u uniform pitch and ofequal diameter from neck to point, or tapering or gmlet-pointed, asrequired, by using sliding templets of the necesl sary shapes for suchforms.

To enable others skilled in the art to make and use my invention, I willnow proceed to describe its construction and inode of operation.

I form the housing A A and bed-plate B of one casting, and secure it toa properfoundation by holding-down bolts in theusual manner. In theupper part of this housing I mount, in suitable bearings, the shaft C,having adriving-pulley, D, on one of its ends and a balance-wheel, E, onthe other, and having, also, the eccentric F in its middle part, betweenthe sides of the housing, as shown `by dlotted lines in Fig. 2. Thisshaft and eccentric should be driven with a speed of about ten hundredrevo.- lutions per minute, but a greater or lesser speed, within properlimits, may be. used. The machine, however, should be run at a highspeed, so as to impinge the dies with sufficient i'orce upon the blankor bolt by a small lnotion of the jumper, which is desirable. The throwof the eccentric F is accordingly iliade about one inch, and, thevibration of the j um per bein g. thuslimited, a high speed can beadopted with safety, and thereby give greater productive capacity to themachine. s

The jumper or stamper G is made with a hollow cylindrical head, which isbored out true to embrace and fit the eccentric F, and is secured inposition bythe radius II, which is jointed to it at the foot u, back ofthe die-bed,

and also to the housing by the journals of the rocker b, which havebearings in the arms I, cast on either side at the back of the housing.The radius H being thus attached to the -foot oi?. the jumper or stamperG andy thehousing AA, the top die is retained in-y proper place for thework it has to peform, notwithstanding the vibration of the upper partof the jumper by the eccentric F.

Between the sides of the housing A A and beneath the jumper or stamperG, I place the cast-iron anvil-block J, and confine it to its place bythe guide-plates K K, bolted to the front ofthe housing, and embracingbetween them and the housing the'slides c c, cast upon the sides of the`anvil-block J, or by any other convenient arrangement that will securea vertical movement of the anvil in the housing. This anvil-block shouldbe of sufficient weight to give effective resistance, by` its inertia,to the force ofthe blows impinged upon the blank bolt or screw by thestamperG; but, for the purpose of reducing the friction upon the edgesofthe sliders that carry the anvil, I connect with it, by means of aprojecting head which enters, the vsocket d, cast in the anvil, thecounter-balance L, but of less weight than the anvil, and support it bythe center pin, f, passing through the shank of the countenbalance, andthe projections M, cast on either side of the housing at the back. Thiscounter-balance not only relieves the sliders of a large portion of theweight they would otherwise have -to sustain, lbut also assists theanvil, throughthe upward action nf the head d, in resisting the blowsimpinged upon it by the top die. The counter-balance L, however, may bedispensed with, as the machine will work effectively without it, as Ihave experimentally ascertained. Nevertheless, it is of advantage in theworking ofthe machine, for the reasons I have stated.

. In the lower part of the stamper G, and in the correspondingupper'part ofthe anvil J, I insert, byy means of dovetails or in anyother suitable manner, the steel swagingdies/AN N, having upon each, inreverse, a few threads of the required form and pitch lof screw. Inpractice-I have found'that-two:threads in each of'the dies aresufficient to produce a wellformedjscrcw. 1 These threads Imake-straight atfbothedge and bottom,as upon a flat surface, so thatthey` may approach closelyVtoward-each otherA when'required, which isessential to the formation of Agimlet-pointed' screws -as well as 'inthe making of screws that havea `varyimg diameter; and they should beproperly tempered, and soadjusted in relation to eachother that theyshalloperate correctly togetherrin forging a continuous screwthreadvaround and'upon the blanks or bolts somewhatvtedious, I have devisedalmechanism for the purpose, Which'is shown in Fig.- 11.

The rocker b rb, which is attached'to and supported by -the arms I, caston the back ofthe housing-A A, as-showny in Fig..1,'as before described,has in-its middle part andat right angles-with it,-a socket, g,throughwhich is passed the rear endl otl the radius H, upon which portion ofthe'radius a'screw iskformed andfltted with two nuts, h h, one at eitherend of thesocket g. s

The'head a of thelradius being jointed to the footof the'jumper Gr, thatcarries the top die, 'asy before described,anydegree of adjustment,either rearward orforward, can be given tojthe top die by mean'sof thelnuts h h,to suit the position ofthe bottom die.:

The anvil-block J is elevatedand depressed within the housi1ng, so\as toincreaseor diminishthe `distance between the topand bottom dies, asrequired, byAv means ofthe sliding templets or sliders P P. (Shown inred lines'in Fig-.1 and n.1 `vertical cross-section in Fig. 2.) Thelower edges of j these sliders are made straight and rest upon thebearers Q Q, cast on or attached to the inner side of the housing A A,as shown in Fig. 2, and their upper edges take under and support thetrunnion-like projections m m of the anvil-han gers n n. Theseanvil-hangers should be of wrought-iron, and have the bearing-surface ofthe parts m m faced with steel, and should be securely attached to theanvil, so as to sustain its weight and the force of the blows impiugedupon it in the screw-forging process.

The upper edges of the sliders PP should be case-hardened or chilled ifof cast-i ron, or faced with steel if made of wrought-iron, and shouldbe of such form or shape as will cause the anvil to fall sufliciently topermit the passage of the blank bolt between the 'dios while the machineis in motion` without .being struck by them '5 but theirshape must alsobe suehthat upon thesliders beingdrawn outward alittle distance theywill elevatethe anvil, and with it the blank bolt till the dies bothabove and below strike .into it. sufciently. to form the screw.

The shape ofthe bearing-edges ofthe sliding templets or slidersisvimportant, and is thus determined: The breadth of ythe-slider nearthe front end, immediately belowthe bearing of the anvil-hanger, shouldbe such `that the die of the 'anvil shall be sufliciently low to allowthe shank of the blank or bolt to repose on it clear of theaction-offtlietop die while in motion. It should then slope upward andrearwardfromthat point till the threads of the vdies shall strike intotheblank'to their full depth; then continue parallel from that point tothe back end, as shown in Fig. 7, if the screwis to be of the same sizeyfrom-neck to point. If,l1owever,the screw-is to have arginilet-point,then the back end of the slidermust also be inclined upward'A andlrearward, as shown in Fig. 8, so as to bringthe-dies graduallytogethertillthey almost-touch each-other at the .point of the bolt 5- but if thescrew is to be of tapering formv from the shank to the point, the slidermust be' inade of tapering form also, as shown in Fig. 6 and, in likemanner, if swelled or Y concave taper-screws are to be forged,theinclined bearing-edges vof the sliders must be rounded or hollowed tosuit such-forms of screw;

. .lf screws of uniform diameter-only. are required the anvil mayfbeelevated or depressed infsuch case by 'means of a revolvin gf orpartially-revolving cam of proper shape, instead of by thesliding-templets above-described,

whichcam maybe operatedbya hand-lever Outward as eentralehank, I placetbe guide-1 serew S,by passing the .Shank .0f .the Lollgl helder throughit, and `secure it thereto by the? mit 1l Q11 the enter end eftbe shank,.the .other legef tbe tenes. `being.seenred to the shank-' leg by thelinker binderg on .eempressing;1` them toward A,each ether, es.practiced .by .blaekf Smiths, e0. t0 held tbe blank bolt i tightly?between the jaws. l

Thegnidefsereiy .S Werks iu a half-nuten screwed bearing, t, in thestationary pedtal,

T, Figs l and ,3.,fwbieb should .be `se placed? reletiyely with the.feigingfilies N .iS-that there l will be Sufiieientflength 0fguide-seres: between i tbe .tongs and the screwed bearingn the ned-festai te` `eeinnlete the. `required length .of screw. nnenthebelt- Qnibeoliter end of theguide-serew Sa bearing er jeurual, e, is filmed,having aeolf lar oneaehsideof it. Into this bearing ork journal is ttedthe lyeke V, Figs. 4. and `5., andi Shown in erossseetion byred lines inEig. 1. Tetliie yoke isettaebed the sliding rods .w wf connecting withthe sliding templete P E, as, shown in Figs. aud 6 and by red lines iuFig. l. These slidingrodspass threngh holesi er Steady-bearingswein theunnerpert of; the pedestal il?, as` shown in Fig.` 3. l By tbisiarrangelnentot" theparts the sliding templetsl P P are combined withlhegnide-serew S, andi are drawn Ollllyardbyits outward. moyemennl andWilli. tbe saine degreeef metien, thus eensing the sliding templets and-the bolt nponl which the rewislbeing-ibrged tomereont-l ward togetheras the operation progressesq 0n eonqpleting the serew the slidingtemplets `are rnn baeliso as, to drop the anvil fortbereceptieno'another` blank bolt.` rllhis I ziccginplish by p ushin home the yoke Vby hand, whieb ineleof returning` the. slidingilelnplets` l findeuenreife. thepnrpese. eflieiently.

TQ tbeeuidefserew S. is;attaehedtliesmooth` liiliuieilwbeel Y, forth@purpose .of retatingg it and `the tongs and belt by hand ,buh iflllfe*barred, this. may be delle elllemillly bl" substituting a cog-Wheel forthe SmOOLh handiiibeel, .and eeusing a lenig: pinien, freeeiring;

ngetion from theieeeentrieshaft, t9 Work into it, so as, todgeepjn`gear` dnringthe whole t1av- @ree Of tbeserew, which will carry the`Wheel freni theinnerto; tbebllter end ofsnehl pinion.

A simple mechanism for sueh automatic lilbvelbentis elleiyn `in .Fige land 2; by `blue. linee.. i

Upon the-Geceutriershaft .C is a smallpulley, a', operating by means ofthe beitel, a larger. pulley, bl, supported by thepedeSt-al T- UDCH.`thespindleef the pulleybfisa small beyel-pinion, di, gearing intethebevel-.wheel f', attbe inside nf-the pedestal T, its spindle passing:through thepedestal, Where it has a bearing t0 the outer bearing on thebraelietg, and earryingthelongh pinion k', betbrelzefenred toi asgearing into tbelarge Wheel Yof the gnideqserew S. This train ofgearingsheuld be` so proportioned as to giveaeireuniferential motiontothe bolt `of about one-sixteenth of an ineb, more or Less, for eachblow impin ged .upon :it .bythe fergingdies.

Wbenleng boltsareitofbeserewed by this maehine Athe ten gs. may bedispensed with, and Athe gnid new `audits Rotating Wheel be.plaeeilnnenthe boltfitself and seemed `theretese este :eerry itproperly, ivhenthe .operation `wi ll be the same as already deserbed.

F91 the pnrpeee. ef seeming .centre-.l lpesi- ,tion et' tbebolt .orblank inthe forgin'gfdies 1I.

.the .ereesfber `Zto the sliders P P, having bearing .er elevis, y, init for thereeeptien `.ef the shank er'iieek .of the beit. This bearingenel. leyeeeorrliilglytravelswith the belt, giving enteral Asupportbetween the dies freni tbe menientlit enters .the .machine till it.ebmiles eutlnisbed,

The tongs ARywitb its gilillerserew'S and 1=o tetingiwbeel Y, are.detaebable ifrem the milebine as enepiene-,se as te reeeiire erdisenge-g `tbe belts while' ent .et the maehiue. I aee'ordillgly'@OllSiruebitS `beari,ugs se as to 'permit its free intrediietibn teQnremoral from the. `maebine Witheet .interrupting its speed.. Thebeeringor eleyis y, the serewhearngt, and .the bearingin the vynke'l aretherefore mede enen atltep, .so that tbetepgs, with ablilllk 0F boltalld`the guidefserew and wheeirerlnbe Dleeedill er .talrenfrointbe maehinewhile ib uisrunning atfnll speed.. Theweigbtfofrtbis .delaebflble `plrtor apparatus is snfeient, if ,properly,prepertieneih Le keep it tb itsbeer-ings, espeeially if operated :by hand, wbieh .Causes dbwnward.pressure 1111011 the guideeserew; but when nnerated aute- `matieallythe wheel Y shouldv be of `extra Weight, S0., .Re tekeep it in l gearwitbitbeileng pinien; en a tep nuterbeering, es:` shewnin Fig, 12,-useditoipreSS ufponfthe guide- -serew'bymeans of .thehandjlever A,which is l jeinted te the pedestal illat a.'4,.andlean be raised up andset back out ef thexwey when required, as shown by the drawiugsloiithispart *infblueilines..` At the baerk end of tbie lever there is aprejeetioinblgto act as a stop., by whiehthelenerlis.heldup .and in .a.eonvenient ,pQsit-ioll, `for. tire hamlet-the operette?,

A. belt er blank, being duly heated, 'is grasped by the tongs R andrfirmly Secured tbeleill by tbelink` erbinderq, Itistbenplaeed in themeehine bypassingit threughthefneekbearing 0e @levis y; into the. space.between the forging-.dies N N, the .gnidezserew Sdrepping :intotheserewed bearingt in the `pedestal T, and tbejeuinalot-the.guideserewinto the .bear-ing made f0.1:` itsreeeptien in theyoke V of the slidingrods w w, the-.jumperQretampel G beiugin the.liueantimelatlfull speed.The Wheel Y of the gnidefserew is then rotated with` a. direction ofmotion that veillieause` the f Sere W: t0; mooier outward teftliefrent,an el thereby retate aud bringltheiholt `outward with it While pasing.tbrOu gbl'nld.receivingatheaetien of tbe fergingdies, andLrmn whichl,it emerges a.completely-formed Serew.

In this maelrine the motionsfof bot-h the` anvilyarldl :stain/per areApositive or ofleertain` and to compensate for wear or for otherpurposes,

it will be necessary to set the dies out to the required extent byliners,as usually practiced by machinists in adjusting the height ofdies -in the die-beds; but to accomplish this object with greaterfacility I have devised the mechanism shown in Fig. 9, and in which thehangers an are extended down below the bottom of thel anvil in groovesmade in it for that purpose, as shown in Fig. l0, where theyareconnected by the cross-piece c, through whichis tapped the screw d,bearing upward against the anvil, and upon which itrests. By elevatingordepressing the anvil in the hangers by means of this screw any degree ofadjustment can be given to the space between the dies without disturbingtheir position in the die-beds.

The bolts upon which screws are to be formed by this process beingheated, as in the ordinary operations of forging, they will impart aninjurious heat to the dies it' it is not counteracted. It will thereforebe necessary to cool the dies from time to time during the operation, orimmediately upon the withdrawal of the bolt from the dies, which may beaccomplished by directing small jets of water against them at suchintervals, either by hand orby an attachment to the machine itself, sothat o-n the nished bolt being withdrawn jets of water shall be directedagainst the dies, which may be done by connecting, for example,

vone of the sliding templets or rods with the faucet of the water-pipe,or it may be done by the attendant stepping on a treadle connectlng withsuch faucet or by any other suitable In forming the threads of screwsupon bolts by forging, as herein described, the material from betweenthe threads is worked into the bolt, thus economizing that portion ofthe material which is unavoidably wasted when the thread is produced inthe usual manner by chasing or cutting dies. Forged screws are also muchstron ger than chased screws of equal size, because the interior iron ofthe bolt, which in round-rolled iron, is of inferior strength, isconsolidated by the process, while an unbroken relation is preservedbetween the thread and the body ofthe screw, the fiber of the iron beingcontinued through all the undulations of the screwed surface.

This forging-machine is principally intended to manufacture screws forentering and holding in timber and requiring a coarse pitch with a deepthread, usually of serrated form, such as the screws for attaching thearmor-plates of war-vessels to the timber and the screw-spikes forfastening railroad-rails to the cross-ties, in

either of which cases the forged screws would be of about double thestrength -of chased .screws made from the same description ofiron.

rI he stamper being operatedf Its application, however, is not limitedto such kind of screws, as itwill manufacture screws of common form, tobe used with metallic nuts,

with sufficient accuracy for some purposes;

'but such forged screws can be. passed with rapidity, when cold, throughfinishing-dies, it being only necessary to take off a very small cut togive them a fine bearing-surface, and thereby produce a screw in whichthe best finish and the greatest strength would be combined.

In this specification I have described thc construction and operation ofa practical machine which I have built and used; nevertheless I do notconne or limit myself to the exact details and arrangements hereinshown, but claim the right, under this patent, to vary the same asconvenience or the purpose to which it 4may be applied will require,while the principle of my invention, as herein described, remainsunchanged.

Having thus described the nature, construction, andl mode of operatingmy improved screw-forging machine, what I claim therein as my owninvention, and' desire to secure by Letters Patent, is-

1. The method of forming screw-threads upon metal bolts by means offorging-dies of proper shape, in combination with a guidescrew androtating wheel, all constructed and arranged substantially as described.

2. The combination of the tongs and guidescrew withthe forging-dies andtemplets, constructcd and operating substantially as described.

3. The combination of the clevis with the Vsliding rods or templets, soas to sustain and move with the bolt or blank while it is under theaction ofthe screw-forgin g dies, constructed and operatingsubstantially as described.

4. Controlling the space between the dies, operating as described, asthe operation progresses, by means of sliding templets or theirequivalent, so as to forge screws of uniform diameter or taper, orgimlet-pointed, substantially as described.

5. The combination of the sliding templets with the guide-screw by meansof the sliderods and yoke, so as to be operated by it with an equal andsimultaneous retractive movement, constructed and arranged substantiallyas described.

6. The combination, with screw-forging machinery, of the open bearingor-clevis in front of the dies and the open screwed-bearing in thepedestal for the guide-screw, so that a blank or bolt and the detachableapparatus by which it is held and rotated can be safely andexpeditiously placed in or removed from the machine while in motion andwithout interruption to the speed, substantially as described.

7. The straight-threaded forging-dies, in combination with the jumper cand anvil-block J, constructed and operating in the manner and for thepurpose substantially as described.

8. The combination, in a screw-forging maupon metal bolts by operatingupon and completing them from the neck or shank toward the point by themeans and in the 'manner substantially as described.

JOHN OOOHRANE.

Witnesses:

A. DE LACY, ANDREW I. TODD.

